@PRRronbh posted:I have always presumed 2-rail to be DC vs AC for 3 rail. So in that is the answer. AC much easier to work with for all ages.
Ron
The first O Scale trains on 2 rail track, or out side 3rd rail had AC motors Miniature permag. DC motors, became available just before the war ( AC toy train motors will run on DC, before most households had electricity they ran in wet cell batteries) AS far as ac , easier to work with, , all the other scales Z, N ,TT , HO, S , (Existed before AF) O Scale, Gauge 1and F and all the Ng variants, all run on 2 rail track, and all have DC motors .